It is known a system for cellular communications, for example, GSM whose Radio Subsystem being also referred to as “Subsystem of base stations”—BSS (Base Station Subsystem) comprises base stations BTS (Base Transceiver Station), mobile stations MS (Mobile Station) and controllers of base stations BSC (Base Station Controller). Space distributed base stations form a coverage area and provide reception and transmission of messages from mobile stations MS and to them. Base stations communicate with the controller of base stations through corresponding wireless, cable or other communication lines via some standard interfaces. In GSM this interface is designated as A-bis interface (see, e.g. Asha Mehrotra. GSM System Engineering. Artech House, Inc., 1997, 450 p., as well as Zakirov Z. G. et al., Cellular communications of GSM standard, M.; Eco-trends, 2004, p. 9).
Base station comprises transceiver and antenna modules which realize transmitting—receiving messages in a band of operating frequencies, and a digital unit of distribution and switching DXU (Distribution Switch Unit) providing a system interface of each BTS with BSC by means of cross-switching digital data flows of transport network (E1) and separate time intervals (time slots), control and interaction with all other components of the base station, in particular, with controllers of transceivers.
In respect of a technical essence the closest prior art is a system for cellular communications comprising a switch subsystem and a base station subsystem (a radio subsystem) which are interconnected therebetween, the base station subsystem comprises Q base stations, where Q—an integer; a controller of base stations and mobile stations being coupled through radio channels of operating frequencies of the system for cellular communications with corresponding base stations; herewith each base station comprises serially coupled an antenna-feeder module of operating frequencies and a digital unit of distribution and switching whose first input-output is input-output of a base station for a connection via a corresponding communication line with a controller of base stations (see Y. A. Gromakov, Standards and systems for cellular communications. M. Eco-trends, 2000, p. 239).
Practical implementation of the known system, however, is connected with a raw of drawbacks.
Firstly, a placement of a base station is realized, as a rule, in leased rooms of buildings or in weather-proof containers placed outside a building, a rent for a leasing of rooms constitutes tenths of millions of US dollars per year. Herewith, a connection of transceivers of a base station with antennae to be placed on towers and masts is realized through expensive coaxial cables, an efficiency of connection is reduced because of attenuation of signals at reception and transmission being introduced by the cable. At standard value of transmitter output of 20 W of a base station (for example, BTS Motorola), a height of the mast (70-80) m (the attenuation introduced by the cable constitutes ˜3 dB), output of a signal being fed to the antenna constitutes no more than 10 W that reduces an antenna radius of coverage by 20%. Besides, at reception of signals the attenuation of the received signal by 3 dB results in reduction of a communication range between a mobile station and a base station also by 20%.
Secondly, a usage of radio-relay lines (RRL) for connection of BTS and BSC requires a mounting on an antenna tower of a corresponding equipment and transceiving antennae. Typical specifications for an antenna tower provide for a placement of two types of an equipment and antennae. Taking into consideration feeder cables, antennae for cellular communications, RRL and cables of electric power supply a total pay load to a tower may exceed 800 kg that determines corresponding high requirements to a tower structure of a base station.
In respect of a technical essence the closest prior art for the second invention is a base station of systems for cellular communications comprising serially coupled an antenna-feeder module of operating frequencies, a module of digital transceivers of operating frequencies and a digital unit of distribution and switching whose first input-output is first input-output of a base station for a connection with a controller (see Z. G. Zakirov et al., Cellular communications of GSM standard—M.; Eco-trends, 2004, pages 85-90).
The known base station does not provide, however, an extension of a channel capacity of the system since comprises only transceivers of operating frequencies and does not include an apparatus which provides a transfer of additional channel capacity at frequencies of retransmission.
In respect of a technical essence the closest prior art for the third invention is a repeater of signals of base stations which is used for an extension of coverage area in exiting systems of mobile communications including GSM: band, channel as well as frequency spectrum transit systems, for example, 900 MHz⇄1800 MHz (see, for example, A. A. Kurochkin, Alternative RF planning solutions for Coverage Deficiency, Bechtel Telecommunications Technical Journal, December 2002, pp. 37-47).
The known apparatus provides, however, only an extension of a coverage area, but “takes away”, herewith, a part of a channel capacity of the base station the signals of which are retransmitted. That is, these repeaters do not allow increasing total number of communication channels in a cellular system.
In accordance with the given inventions into a system for cellular communications are introduced new network elements: a radio repeater CTR with a transition of a channel capacity (CTR—Capacity Transit Repeater) and a base station with retransmission of signals—BTS-R (BTS-Repeater).